Adam Clarke on Isaiah 60:7

The rams of Nebaioth shall minister unto thee - Vitringa on the place understands their ministering, and ascending or going up on the altar, as offering themselves voluntarily: ipsi se, non expectato sacerdote alto, gloriae et sanctificationi divini nominis ultro ac libenter oblaturi. "They, waiting for no priest, go and freely offer themselves to the glory and sanctification of the sacred name." This gives a very elegant and poetical turn to the image. It was a general notion that prevailed with sacrificers among the heathen, that the victim's being brought without reluctance to the altar was a good omen; and the contrary a bad one. Sabinos petit aliquanto tristior; quod sacrificanti hostia aufugerat. Sueton. Titus, cap. 10. Accessit dirum omen, profugus altaribus tauris. "It was an omen of dreadful portent when the victim fled away from the altar." Tacit. Hist. 3:56. - L.