The gift could be frankincense or myrrh, it is not clear. Here is Reges Tharsis by John Sheppard , sung in this YouTube by the Sixteen.
Reges Tharsis et insulae munera offerent,
reges Arabum et Saba dona
(Domino Deo) adducent.
Et adorabunt eum omnes reges terrae,
omnes gentes servient ei.
Gloria Patri et Filio et Spiritui Sancto.
The kings of Tarshish and the islands will offer tribute, the Kings
of Arabia will bring gifts to the Lord God; and all kings will adore
him, and all nations will serve Him.
Glory be to the Father, and to the Son, and to the Holy Ghost.