Allah has permitted trading and prohibited Riba (usury/interest). Allah (Exalted be He) says:
...whereas Allâh has permitted trading and forbidden Ribâ (usury).
One of the lawful transactions is selling in installments. This is denoted by Allah's saying:
O you who believe! When you contract a debt for a fixed period, write it down. Let a scribe write it down in justice between you. Let not the scribe refuse to write as Allâh has taught him
Al-Qurtuby said in his exegesis of this Ayah (verse of the Qur'an): "This Ayah includes all debts and postponed payments according to the consensus of scholars."
It was reported in the Two Sahih (authentic) Books of Hadith (i.e. Al-Bukhari and Muslim) on the authority of
`Aishah (may Allah be pleased with her)
Barirah was sold by her owners in return for nine Uqiyyahs (40 Dirhams of silver = 119 grams) in installments, one Uqiyyah every year. The Prophet (peace be upon him) approved of such a transaction. Therefore, it is evident that dealing in the way mentioned by the questioner (Part No. 13; Page No. 149) is permissible according to the above-mentioned proofs.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.