This combination to represent whiteness occurs in Dan 7:9, and Isa 1:18. Snow, in Psa 51:7.
Flame of fire
Compare Dan 10:6. Fire, in Scripture, is the expression of divine anger. The figure may include the thought of the clear and penetrating insight of the Son of Man; but it also expresses His indignation at the sin which His divine insight detects. Compare Rev 19:11, Rev 19:12. So Homer, of Agamemnon in a rage: “His eyes were like shining fire” (“Iliad,” i., 104); also of Athene, when she appears to Achilles: “Her eyes appeared dreadful to him” (“Iliad,” i., 200).