Charles Ellicott Commentary Exodus 30:7

"And Aaron shall burn thereon incense of sweet spices: every morning, when he dresseth the lamps, he shall burn it." — Exodus 30:7 (ASV)

Aaron shall burn thereon sweet incense (Hebrew, incense of spices) every morning. On the composition of the incense, see Exodus 30:34-35. That the offering of incense regularly accompanied both the morning and evening sacrifice appears from Psalms 141:2 and Luke 1:10. That it was symbolic of prayer may be gathered both from those passages and also from Revelation 5:8 and Revelation 8:3-4.

When he dresseth the lamps. Compare Exodus 27:21.