וְעָשִׂ֜יתָ חַ֤ג שָׁבֻעוֹת֙ לַיהוָ֣ה אֱלֹהֶ֔יךָ מִסַּ֛ת נִדְבַ֥ת יָדְךָ֖ אֲשֶׁ֣ר תִּתֵּ֑ן כַּאֲשֶׁ֥ר יְבָרֶכְךָ֖ יְהוָ֥ה אֱלֹהֶֽיךָ׃
Rashi on Deuteronomy
מסת נדבת ידך means sufficient (די) free-will offerings of thy hand (i.e. of thy possession) (cf. Targum on Deuteronomy 15:8, which renders די מחסרו by כמסת חסרונה); everything must be in accordance with the blessing which God has bestowed upon you (אשר יברכך): offer peace-offerings of rejoicing and invite guests for the meal.