John Gill Commentary Numbers 28:4

"The one lamb shalt thou offer in the morning, and the other lamb shalt thou offer at even;" — Numbers 28:4 (ASV)

The one lamb shall you offer in the morning
Every morning, to make atonement for the sins of the night, as the Targum of Jonathan:

and the other lamb shall you offer in the evening ;
or "between the two evenings", to make atonement for the sins of the day, as the same Targum; in which they prefigured Christ, the Lamb of God, who continually, every day, morning and night, and every moment, takes away the sins of his people, through the virtue and efficacy of his sacrifice, (John 1:29) , (See Gill on Exodus 29:39).