Hadithcore
Mishkat al-Masabih, 552

Mu'adh b. Jabal said that he asked God’s messenger what was lawful for him in his wife when she was menstruating, and he replied, “What is above the waist-wrapper, but to abstain from that is better.” Razin transmitted it and Muhyi as-Sunna said that its <i>insad</i> is not strong.

وَعَنْ مُعَاذِ بْنِ جَبَلٍ قَالَ: قُلْتُ: يَا رَسُول الله مَا تحل لِي مِنِ امْرَأَتِي وَهِيَ حَائِضٌ؟ قَالَ: «مَا فَوْقَ الْإِزَارِ وَالتَّعَفُّفُ عَنْ ذَلِكَ أَفْضَلُ» . رَوَاهُ رَزِينٌ وَقَالَ مُحْيِي السُّنَّةِ: إِسْنَادُهُ لَيْسَ بِقَوِيٍّ

References1 variant
In-Book Reference
Book 3, Hadith 248