Ignatius of Antioch (early 2nd-century) identifies Jesus with the "Son of Man" from Daniel 7.
Ignatius of Antioch, Epistle to the Ephesians 20:2, in Gregory R. Lanier, Corpus Christologicum: Texts and Translations for the Study of Jewish Messianism and Early Christology (Peabody, MA: Hendrickson Academic: An Imprint of Hendrickson Publishing Group, 2021), 627 (Logos ed.)
οἱ κατʼ ἄνδρα κοινῇ πάντες ἐν χάριτι ἐξ ὀνόματος συνέρχεσθε ἐν μιᾷ πίστει καὶ ἐν Ἰησοῦ Χριστῷ, τῷ κατὰ σάρκα ἐκ γένους Δαυίδ, τῷ υἱῷ ἀνθρώπου καὶ υἱῷ θεοῦ, εἰς τὸ ὑπακούειν ὑμᾶς τῷ ἐπισκόπῳ καὶ τῷ πρεσβυτερίῳ ἀπερισπάστῳ διανοίᾳ.
All of you, each man in common, should gather together in grace, by name, in one faith and in Jesus Christ—who according to the flesh is of the lineage of David, the Son of Man and Son of God—so that you obey the overseer and the presbtyery with an undistracted mind.