Rashi on Exodus 19:4/רש"י על שמות י״ט:ד׳

1אתם ראיתם YE HAVE SEEN — It is not a tradition in your possession, not in written words do I send a message to you, not by means of eye-witnesses do I attest this to you, but you yourselves have seen אשר עשיתי למצרים WHAT I DID UNTO EGYPT — on account of many sins were they liable to Me for punishment before they came into contact with you, but I did not exact punishment from them except on your account (cf. Mekhilta).

2ואשא אתכם AND I BARE YOU [ON EAGLES’ WINGS] — This happened on that day when the Israelites came to Rameses (the place where they all assembled on the night when they left Egypt) (Mekhilta), because the Israelites were living dispersed throughout the whole district of Goshen and in one brief moment — when they came there to set out and to leave Egypt — they all gathered together at Rameses. Onkelos translates ואשא as though it were [וְאַסִּיעַ [אתכם — viz., ואטלית יתכון “and I made you travel” (cf. the Targum on וַיַּסַע Exodus 15:22); he adapted the expression in a manner that is consonant with the respect due to the Most High God.

3על כנפי נשרים UPON EAGLES’ WINGS — as an eagle which bears its fledglings upon its wings. Scripture uses this metaphor because all other birds place their young between their feet since they are afraid of another bird that flies above them, but the eagle fears none except man — apprehending that perhaps he may cast an arrow at it — since no bird can fly above it; therefore he places it (its young) upon its wings, saying, “Better that the arrow should pierce me than my young!” (Mekhilta). — “I, too”, said God, “did thus”: (Exodus 14:19, 20) “And the angel of God … journeyed etc…. And he came between the camp of Egypt etc.” … and the Egyptians were casting arrows and stone missiles and the cloud caught these (cf. Rashi on these verses).

4ואבא אתכם אלי AND I BROUGHT YOU UNTO MYSELF — Explain this as the Targum does: “and I have brought you near to My service”.