Hanafi
The sources give no view for it here.
سبب القرابة بالمصاهرة
ما سبب القرابة بالمصاهرة؟
Each school’s answer
In our wordsHanafi
Not stated in the sources
Maliki
Not stated in the sources
Shafi'i
Not stated in the sources
Hanbali
Not stated in the sources
The texts
ثَالِثًا: الْقَرَابَةُ بِالْمُصَاهَرَةِ: ١٨ - اتَّفَقَ الْعُلَمَاءُ عَلَى أَنَّ سَبَبَ هَذِهِ الْقَرَابَةِ هُوَ النِّكَاحُ، وَلِمَعْرِفَةِ الْمُحَرَّمَاتِ مِنْ هَذِهِ الْجِهَةِ أَوِ الْمَحَارِمِ. وَأَحْكَامُ ذَلِكَ يُنْظَرُ مُصْطَلَحُ (مُصَاهَرَة، وَنَفَقَة، وَزَكَاة ف ١٧٧، وَصَدَقَة ف ١٧) .
«الموسوعة الفقهية الكويتية» (Kuwait) entry «قرابة» vol. 33 p. 74
From the schools’ own books
Maliki
The sources give no view for it here.
Shafi'i
The sources give no view for it here.
Hanbali
The sources give no view for it here.
What is «in our words» is our standard wording; the books’ texts stay as they are.