Jamieson, Fausset and Brown on Isaiah 44:9

9. (Is 40:18, 20; 41:29).

delectable things--the idols in which they take such pride and delight.

not profit--(Ha 2:18).

they are their own witnesses--contrasted with, "Ye are My witnesses" (Is 44:8). "They," that is, both the makers and the idols, are witnesses against themselves, for the idols palpably see and know nothing (Psa 115:4-8).

that they may be ashamed--the consequence deducible from the whole previous argument, not merely from the words immediately preceding, as in Is 28:13; 36:12. I say all this to show that they are doomed to perish with shame, which is their only fitting end.