I want the explanation of ishmaam

I want the explanation of ishmaam, and those hafs do ishmaam of the 4rth aya of suratul fatiha.

Assalaam alaikum
The detailed explanation of al-ishmaam can be found at the following link: http://www.abouttajweed.com/stopping-on-the-ends-of-words/stopping-on-the-ends-of-words-2.html

Aayah four of al-Faatihah ends with kasrah and is only on a fixed or conjugated dhammah, never on a word ending with a kasrah.  This is four Hafs and all of the different qira'aat, none of them allow on the end of this aayah or any word ending with a kasrah.