Do the prayers of one who did not perform istinja after urinating, due to ignorance of the Shari'ah ruling, become invalid?

The majority of scholars hold that avoiding impurity is a condition for the validity of prayer. However, Sheikh al-Islam Ibn Taymiyyah is of the view that whoever omits a condition out of ignorance is not required to repeat the prayer. Therefore, you are not required to repeat past prayers. You must be careful about purity and cleansing from urine in the future, for neglecting to cleanse oneself and ensure complete discharge of urine is forbidden, and many scholars consider it a major sin. The proof for this is the hadith (definition) narrated by Ibn Abbas from the Prophet, peace and blessings be upon him: "One of them did not cleanse himself properly from his urine," and the hadith of Abu Hurairah: "Cleanse yourselves from urine, for indeed, most of the torment of the grave is due to it."