What is the meaning of Acts 18:21?

* The two F.O.G. Bibles & Commentary below are currently a work in progress.

But as he left, he said, “I will come back to you if God is willing.” And he set sail from Ephesus.

Berean Standard Bible (BSB)

but taking his leave of them, and saying, “I must by all means keep this coming feast in Jerusalem, but I will return again to you if God wills,” he set sail from Ephesus.

World English Bible (WEB)

But{G235} bade{G657} them{G846} farewell{G657}{(G5662)}, saying{G2036}{(G5631)}, I{G3165} must{G1163}{(G5748)} by all means{G3843} keep{G4160}{(G5658)} this feast{G1859} that cometh{G2064}{(G5740)} in{G1519} Jerusalem{G2414}: but{G1161} I will return{G344}{(G5692)} again{G3825} unto{G4314} you{G5209}, if God{G2316} will{G2309}{(G5723)}. And{G2532} he sailed{G321}{(G5681)} from{G575} Ephesus{G2181}.

Strong's King James

(21) but farewelled them and said, "I will return to you again if The אֱלֹהִים Elohim-God wants," and set sail from Ephesus.

The F.O.G*

[21] As he prepared to depart, he assured them, "I will return to you if it is God's will." With those words of hope, he set sail from Ephesus, leaving behind seeds of truth that would soon blossom into a mighty work of God.

The F.O.G Paraphrase

but took leave of them, saying, ‘It behoveth me by all means the coming feast to keep at Jerusalem, and again I will return unto you—God willing.’ And he sailed from Ephesus,

Young's Literal Translation