Дварим (Второзаконие) 16:10

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.

And thou shalt keep the feast of weeks to the Lord thy God with a tribute of a freewill offering of thy hand, which thou shalt give, according as the Lord thy God has blessed thee:

וְעָשִׂ֜יתָ חַ֤ג שָׁבֻעוֹת֙ לַיהֹוָ֣ה אֱלֹהֶ֔יךָ מִסַּ֛ת נִדְבַ֥ת יָדְךָ֖ אֲשֶׁ֣ר תִּתֵּ֑ן כַּאֲשֶׁ֥ר יְבָרֶכְךָ֖ יְהֹוָ֥ה אֱלֹהֶֽיךָ׃