فَإِنْ دُفِنَ وَلَمْ يُصَلَّ عَلَيْهِ: صُلِّيَ عَلَى قَبْرِهِ إِلَى ثَلَاثَةِ أَيَّامٍ فِي الشِّتَاءِ، وَسَبْعَةٍ فِي الصَّيْفِ، وَلَا يُصَلَّى بَعْدَ ذَلِكَ.
Translation: If burial occurs without the funeral prayer, this wording gives three days in winter and seven in summer for prayer at the grave, not beyond.
The text gives a winter/summer period in this edition. Later Hanafi discussions explain the operative limit by the reasonable likelihood that the body has not decomposed; climatic and other circumstances matter.
The rule concerns someone buried without any funeral prayer, not an ordinary wish to repeat a completed prayer.