וַיִּקְרָ֣א יַ֠עְבֵּץ לֵאלֹהֵ֨י יִשְׂרָאֵ֜ל לֵאמֹ֗ר אִם־בָּרֵ֨ךְ תְּבָרֲכֵ֜נִי וְהִרְבִּ֤יתָ אֶת־גְּבוּלִי֙ וְהָיְתָ֤ה יָדְךָ֙ עִמִּ֔י וְעָשִׂ֥יתָ מֵּרָעָ֖ה לְבִלְתִּ֣י עָצְבִּ֑י וַיָּבֵ֥א אֱלֹהִ֖ים אֵ֥ת אֲשֶׁר־שָׁאָֽל׃
Jabes invocou o Deus de Israel, dizendo: Oxalá que me abençoes, e estendas os meus termos; que a tua mão seja comigo e faças que do mal eu não seja afligido! E Deus lhe concedeu o que lhe pedira.
Rashi on I Chronicles
and Your hand is with me that You save me from harm if You will be with me and save me from harm. so as not to grieve me that no injury, pain, or sadness befall me, and he vowed whatever he vowed.
Rashi on I Chronicles
and God fulfilled that which he had requested and he paid his vow. From here proof is brought that when people subscribe to a charity (in public) for a certain cause, they should not vow but give without a vow. Its midrashic interpretation is well known.