Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: "Zakat is not obligatory on the wealth of a minor; zakat becomes obligatory when prayer also becomes obligatory upon him (i.e., when he reaches puberty)." The narrator of this narration, Ibn Lahi'ah, has not been considered reliable.
Hadith Referenceسنن الدارقطني / كتاب زكاة / 1981
Hadith Takhrij«أخرجه الدارقطني فى ((سننه)) برقم: 1981،»