Anupam: Swamiji please give me correct translation and interpretation of Brahadaranyaka Upanishad (6/4/7) and (6/4/18).
Swami Ram Swarup: Nowadays, I am not having time to explain the ved mantras or upnishad shlokas with words and meanings. However, I am telling the idea of the Brihadarannyakopnishad. Brihadarnnyakopnishad shloka 6/4/7 and 6/4/18 are as under-

In the previous shloka 6, the Rishi has briefed about the wife as respected, pure, auspicious wealth and Rishi has told that such lady only deserves to bless the husband with children not other. So, in the following shlokas i.e., 7 and onwards there is no way to insult the wife/ lady. Therefore, the idea of above quoted shloka 7 will be (Sa ched asmai na dadyaat) if the wife does not surrender herself before the husband for procuring children the husband should (enaam kaamam avkreenniyaat) try to control her by sweet speech and the desired matters of the wife (Sa ched asmai naiv dadyaat) if still she does not agree then (kaamam enam yashtaya va panneena va uphatya) the husband should try to show fear that he will punish her [ but here it is not mentioned to punish her. But only to show the fear thereof.] that (Te yashaha yashsa indriyeinn aadadey) oh! My wife, if you will not agree then to save my fame, I shall get you fame along with organs etc., that is I shall maintain total brahmacharya for whole of life, with the result, you will not get any child. Then in the old age you will have to face several sorrows in the absence of children. Therefore, considering the said fear, you must agree with me to get the child.

Therefore, idea of shloka 6/4/8 is as under-

If a person desires to have a learned child who would be able to speak/teach the four Vedas and get long life then the husband should take the “maasaudanam” i.e., dal of “urad” with rice duly mixed with desi ghee to eat, by both. Here, mostly the people become doubtful about non-vegetarian but the word is “Maas” not “Maans”. “Maas” means dal of urad and “maans” means non-vegetarian.

Ramakanth: Priya guruji, In which mantra wearing of yagnopaveet must and should in vedas and following vedas without yagnopaveet can we get moksha?
Swami Ram Swarup: My blessings to you. To wear Yajyopaveet is essential. Ved mantras and the preach of rishi-Munis is considered authentic. Atharvaved mantra 11/5/3 shows the idea of “Upnayan sanskar.”
In this connection, Paar-Giri-sutra 2,2,11 as mentioned below also refers-
“Om Yajyopaveetam paramam pavitram
prajapateyrayatsahajam purustaat,
Aayushyamagram Pratimunch shubhram
Yajyopaveetam balamastu tejah.”