"Hail the Day that Sees Him Rise" is the most popular Ascension Hymn. Sheet Music can be found at this link: https://hymnary.org/hymn/CBOW1994/399
Here are the Lyrics:
1 Hail the day that sees him rise, Alleluia! to his throne beyond the skies. Alleluia! Christ, the Lamb for sinners given, Alleluia! enters now the highest heaven. Alleluia!
2 There for him high triumph waits; Alleluia! lift your heads, eternal gates. Alleluia! He has conquered death and sin; Alleluia! take the King of glory in. Alleluia!
3 Highest heaven its Lord receives; Alleluia! yet he loves the earth he leaves. Alleluia! Though returning to his throne, Alleluia! still he calls us all his own. Alleluia!
4 Still for us he intercedes; Alleluia! his atoning death he pleads, Alleluia! near himself prepares our place, Alleluia! he the firstfruits of our race. Alleluia!
5 There we shall with you remain, Alleluia! partners of your endless reign, Alleluia! see you with unclouded view, Alleluia! find our heaven of heavens in you. Alleluia!
"Hail the Day that Sees Him Rise" by Charles Wesley (1707-1788) was published in 1739 in Hymns and Sacred Poems under the title "Hymn for Ascension-Day." The original poem comprised 10 stanzas.
The tune now usually associated with this text is Robert Williams' melody LLANFAIR, which began in John Parry's collection, Peroriaeth Hyfryd (Sweet Music), in 1837. The tune name is a form of the author's hometown in Wales, Llanfechell. The first uniting text and tune is found in The English Hymnal of 1906.