You must offer up the second lamb in the afternoon. You must offer it up with the same grain-offering and libation as in the morning, as a fire-offering pleasing to G-d.
Numbers 28:8
The Maggid of Mezeritch interpreted the final phrase of this verse as follows:
When a person serves G-d – either through prayer, studying the Torah, or performing some commandment – with “a fire offering,” i.e., with warmth and enthusiasm, it is “pleasing to G-d.”
--Daily Wisdom Volume 3