Where does “Jónatan” come from?

Jónatan (Icelandic) comes from Hebrew יְהוֹנָתָן, from Hebrew נָתַן — gave; to give.

Ancestry of “Jónatan”, step by step

Step	Language	Word	Meaning
1	Hebrew	יְהוֹנָתָן	—
2	Hebrew	נָתַן	gave; to give

Jónatan — Etymology, Origin & Word History | Etymology Explorer