Was in his hand
By metaphor: could. He had the ability or possibility.
("In her righteousness, it is written (2 Kings 24) and he did evil in the sight of the Lord! - which was in his hand to destroy and did not destroy" - Sanhedrin 101, and so: "All the nations in those lands were in the wilderness, and it was not in their hand to show them the way" - Agnon/ Tamol Shilshom, 9).
Translation
Expression (Hebrew)
הָיָה בְּיָדוֹ
Definition (Hebrew)
בְּהַשְׁאָלָה: יָכֹל. הָיְתָה לוֹ הַיְּכֹלֶת אוֹ הָאֶפְשָׁרוּת.
("בִּצְדָקֶיהָ נָמֵי כְּתִיב (מְלָכִים ב' כ"ד) וַיַּעַשׂ הָרַע בְּעֵינֵי ה'! - שֶׁהָיָה בְּיָדוֹ לִמְחוֹת וְלֹא מִחָה"- סַנְהֶדְרִין קג ע"א, וְכֵן:"כָּל הַגּוֹיִים בְּאוֹתָן הָאֲרָצוֹת בּוֹעֲרִים הָיוּ,וְלֹא הָיָה בְּיָדָם לְהַרְאוֹת לָהֶם אֶת הַדֶּרֶךְ"-עַגְנוֹן/ תְּמוֹל שִׁלְשׁוֹם, 9).