يدي + ي in the Qur'an

In the Qur'an there is this verse:

وَمُصَدِّقًا لِمَا بَيْنَ يَدَيَّ مِنَ التَّوْرَاةِ وَلِأُحِلَّ لَكُمْ بَعْضَ الَّذِي حُرِّمَ عَلَيْكُمْ

So بين should make the word after it مجرور but one thing that is confusing me is I don't know what يديَّ is

When I look up the declension table here:

https://en.wiktionary.org/wiki/%D9%8A%D8%AF#Arabic

the closest form is the dual form, يدي but I dont understand the grammatical reasoning.

I understand the extra ي is a pronoun but why is it read as a fatha?