Angelic tongues is a term related to the concept of sung praise in Second Temple period

Second Temple period

The Second Temple period , in Jewish history, is the period between 530 BCE and 70 CE, when the Second Temple of Jerusalem existed. It ended with the First Jewish–Roman War and the Temple's destruction....

 Jewish materials.

Hebrew Bible

Throughout the Old Testament

Old Testament

The Old Testament, of which Christians hold different views, is a Christian term for the religious writings of ancient Israel held sacred and inspired by Christians which overlaps with the 24-book canon of the Masoretic Text of Judaism...

 there is no indication that angels spoke (on earth) any other language than that of men. Nor any indication of heavenly tongues: Psa 148:2 "Praise ye him, all his angels: praise ye him, all his hosts."

Dead Sea Scrolls

Songs of the Sabbath Sacrifice

Songs of the Sabbath Sacrifice

The Songs of the Sabbath Sacrifice, also referred to as the Angelic Liturgy, are a series of thirteen songs, one for each of the first thirteen Sabbaths of the year, contained in fragments found among the Dead Sea scrolls. The Songs were found in 10 fragmentary copies: nine at Qumran and one at...

 is the principal source for angelic tongues at Qumran

Qumran

Qumran is an archaeological site in the West Bank. It is located on a dry plateau about a mile inland from the northwestern shore of the Dead Sea, near the Israeli settlement and kibbutz of Kalia...

. The texts are fragmentary but appear to relate to praise tongues:

• [...] through the wonderful height [...] tongue of purity [...] gods (~yhla), seven [...] 4Q400 3 1, 1-2
• ...Psalm of praise, on the tongue of the fou[rth]...[Ps]alm of [tha]nksgiving, on the tongue of the fifth...[Psalm] of exultation, on the tongue of the sixth...Psalm of [singing, on the to]ngue of the seventh of the [chief] pri[nces,] a powerful song [to the God] of ho[lines] with its se[ven] wo[nd]er[ful songs] 4Q403 1 1, 1-6
• Proclaim his glory with the tongue of all who proclaim knowledge, his wonderful songs with the mouth of all who proclaim [him. For he is] God of all who sing {knowledge} for ever, and Judge in his power over all the spirits of understanding. 4Q4031 1 36-37
• ...The tongue of the first will be strengthened seven times with the tongue of the second to him....{this is repeated for the series up to the seventh}... 4Q403 1 2, 27-30

It is not clear whether the angelic tongues are coherent, intelligible to man. However since Songs of the Sabbath Sacrifice is itself related to sung praise at the Qumran community, there is a parallel with coherent angelic praise tongues in Testament of Job.

Testament of Job

The pseudepigraphical Testament of Job

Testament of Job

The Testament of Job is a book written in the 1st century BC or the 1st century AD...

 (ca.100BCE-100AD) contains a conclusion which is believed to relate to the compiling of the hymnbook used by a Therapeutae

Therapeutae

The Therapeutae were a Jewish sect in which flourished in Alexandria and other parts of the Diaspora of Hellenistic Judaism in the final years of the Second Temple period. The primary source is the account De vita contemplativa by the Jewish philosopher Philo of Alexandria who appears to have...

 community. Job gives one of his daughters "a cord" (a string instrument of some kind?)

• "And she took on another heart—no longer minded toward earthly things—but ecstatically in the angelic dialect, sending up a hymn to God in accord with the style of the angels. And as she spoke ecstatically, she allowed “The Spirit” to be on her garment." (T. Job 48:2-3)

Job’s other daughters likewise took on “the dialect of archons”, “the dialect of those and the “dialect of the cherubim” (T. Job 49:1-50:3). The “cherubim” are also mentioned Songs of the Sabbath Sacrifice as blessing God (4Q403 1 2, 15, cf. 4Q405 20 2, 3). These angelic tongues appear to be coherent, intelligible.

There is parallel description of sung prophecy among the Therapeutae in Alexandria

Alexandria

Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

 by Philo

Philo

Philo , known also as Philo of Alexandria , Philo Judaeus, Philo Judaeus of Alexandria, Yedidia, "Philon", and Philo the Jew, was a Hellenistic Jewish Biblical philosopher born in Alexandria....

, but no mention there of angelic tongues.

New Testament

A possible reference to Jewish practices of angelic tongues is 1Co13:1 "If I speak in the tongues of men and of angels, but have not love, I am a noisy gong or a clanging cymbal." The distinction "of men" and "of angels" may suggests that a distinction was known to the Corinthians. If a distinction is intended then 1Co14:10 "There are doubtless many different languages in the world, and none is without meaning" may imply that "tongues of men" were intelligible, whereas 1Co14:2 For one who speaks in a tongue speaks not to men but to God; for no one understands him, but he utters mysteries in the Spirit." refers to angelic tongues. The problem with this is that the "angelic" tongues documented at Qumran and among the Therapeutae appear to be inspired, but coherent and intelligible, sung praise. Against this is the view of Dunn that "It is evident then that Paul thinks of glossolalia

Glossolalia

Glossolalia or speaking in tongues is the fluid vocalizing of speech-like syllables, often as part of religious practice. The significance of glossolalia has varied with time and place, with some considering it a part of a sacred language...

as language".