Thomas D. Seymour, Commentary on Homer's Iliad, Books I-III

[555] After the rather harsh reply of Zeus, Hera plays one trump card after another, showing that she knew not only the person concerning whom she had asked (v. 540) but also what Thetis had requested, and what Zeus had promised.

παρείπῃ: should persuade, i.e. lest it prove true that she has persuaded; anxiety about a fact of the past, for which the aor. ind. is used in “δείδω μὴ δὴ πάντα θεὰ νημερτέα εἶπεν ε” 300, but cf. “ἐξελθών τις ἴδοι μὴ δὴ σχεδὸν ὦσι κιόντες ω” 491.

556 = v. 538.—This is not spoken out of special animosity to Thetis, for whom in fact Hera had special affection; Hera claims Thetis as a sort of foster-child, “ἢν ἐγὼ αὐτὴ ι θρέψα τε καὶ ἀτίτηλα καὶ ἀνδρὶ πόρον παράκοιτιν Ω” 59 f. whom I myself bred and cherished and gave as wife etc. According to a myth found in Pindar (Isth. viii. 30 ff.) and Aeschylus (Prom. 906 ff.), both Zeus and Poseidon strove together as rivals for the love of Thetis, but bestowed her upon Peleus on learning from Themis that this goddess of the sea was destined to bear a son mightier than the father.