See Berishis 2:12 וּֽזֲהַ֛ב הָאָ֥רֶץ הַהִ֖וא ט֑וֹב translated as “And the gold of that land is good”
Kol Tuv = “all the best”
See Bereishis Perek 46:18 where Paroh tells Yosef: וְאֶתְּנָ֣ה לָכֶ֗ם אֶת־טוּב֙ אֶ֣רֶץ מִצְרַ֔יִם which is translated as “I will give you the best of the land of Egypt”
Ohh!! “Kol tuv” is what you say to someone, like wishing the person the best!
Thank you 🙂
Once, someone said “kol tuv” to me before hanging up the phone. She was really sweet, and Israeli. So I responded with “kol tuv,” too (mirroring her, but unsure of why I was saying “tuv” vs. “tov”)