As @afnrf said it's not really clear what is troubling you! But i'll try to give an answer by interpretation the two Verses according to tafsir books:
Is talking about Zayd ibn Haritah (May Allah be pleased with him) and the Marriage of our Prophet (Peace be upon him) with his former wife Zaynab (May Allah be pleased with her): Zayd was adopted by our Messenger (Peace be upon him) in Jahilya, so everybody called him "Ibn Mohammad" till the revealing of the part of the Verse which "quotes" that adopted sons are no longer considered sons! Our Messenger (Peace be upon him) married him to his cousin (The daughter sister of the father of the Messenger Omaymah bin 'abd al-Muttalib) Zaynab bint Jahsh al-Assadiya (May Allah be pleased with her), but after one year of marriage they had a dispute (some say because she was considering her husband as base-born while she was a noble of Mekka) and Zayd went to our Messenger (Peace be upon him) to complain about her and our Messenger (Peace be upon him) told him:"Keep your wife and fear Allah" but at least they divorced and our Messenger has married her later. According to some Narrations (tafsir ibn Kathir) he already knew he will marry her one day that's why Allah said
"while you concealed within yourself that which Allah is to disclose"
Now the difficulty was that Man couldn't marry their son's wives even in the case of an adopted son's according to the customs of Jahilya. So the words
"We married her to you in order that there not be upon the believers any discomfort concerning the wives of their adopted sons when they no longer have need of them"
Made an end to this custom and declared that Adoption is not allowed in Islam or at least doesn't count as parenthood when it comes to shari'a! From that time on Zayd was no longer called Zayd ibn Mohammad but Zayd ibn Haritah!
According Tafsir ibn Kathir there's a narration in Musnad al Imam Ahmad telling that it was Zayd himself who was sent out from our Messneger (Peace be upon him) to ask her for marriage after the end of her 'idah! And here's a Version from Sahih Muslim.
For more details see this ahadith which give some information about the story:
In Jami' at-Tirmidhi
In Sahih al Bukhari narrated by 'Aisha and Anas ibn Malik
Is mentioning the Relation between the Messenger (Peace be upon him) and the believers and also the high position of his wife's, with which Allah has honored them!
As it's unclear what is troubling you i will just quote some ahadith which support the meaning of the Verse, but feel free to ask if you are looking for an explanation of an exact matter!
- The position and relationship of our Messenger for the believers:
In Sahih al Bukhari (but also quoted in other books with similar Words from different sahaba (May Allah be pleased with them) and an other Narration quoting a part of the Verse.
- "And those of [blood] relationship are more entitled [to inheritance]"
- For the part "And his wives are [in the position of] their mothers" their are many different interpretation, on what is the meaning of Umahat al-mu'minyn and to whom they are considered mothers which are described and discussed in tafsir books like ibn Kathir, al-Qurtobi
(who quoted a statement of 'Aisha saying to a woman that she is only the mother of the male Muslims, al-Qurtobi rejects this and says that the mothers of believers are mothers for both male and female, he also discussed the matter whether looking at them is halal, as a mother is allowed to look at for her "children" as she is a mahram, so it's a question about the significance of mother and the mahram status, whether it only means one isn't allowed to marry them after his death or the "known" mahram status of a mother. He also discussed the status of woman our Prophet has divorced during his lifetime, so the most prevalent opinion in this is that if the marriage was consummated the status of mahram applies to her also, there's also the opinion that this applies to any woman he married or they are considered after the divorce as any other woman)
and at-tahrir wa at-tanwir
(who added that woman whom were not his legal wives or with whom a marriage was consummated, so what his right hand posses and women to whom he got married to but divorced before the marriage was consummated are not considered as "mothers of believers") ...