"O people, you eat of two plants which I do not think are anything but bad, this onion and garlic. I have seen the Prophet of Allah (ﷺ), if he noticed their smell coming from a man, ordering that he be taken out to Al-Baqi'. Whoever eats them, let him cook them to death."
Sunan an-Nasa'i Book 8, Hadith 21
← Previous Hadith "The Messenger of Allah (ﷺ) said: 'Whoever eats of this plant' - the first time he said 'garlic' then he said, 'garlic, onions and leeks' - 'let him not approach us in our Masjids, for the angels are offended by that which offends mankinds.'"

In Fath, Al-Bari, Ibn Hajar is of the opinion that it was Ibn Juraij who was talking, explaining that 'Ata' - who reported it from Jabir - narrated it both ways.

Sunan an-Nasa'i Book 8, Hadith 20 Next Hadith → "When the Messenger of Allah (ﷺ) wanted to observe I'tikaf, he would pray Fajr then enter the place where he wnated to observe I'tikaf. He wanted to observe I'tikaf during the last ten days of Ramadan, so he commanded that a Khiba' (tent) be pitched for him. Then Hafsah ordered that a Khiba' be pitched for her, and when Zainab saw her tent she ordered that a Khiba' be pitched for her too. When the Messenger of Allah (ﷺ) saw that he said: 'Is it righteousness that you seek?' And he did not observe I'tikaf in Ramadan, and observed I'tikaf for ten days in Shawwal (instead)."

Al-Khiba': "One of the house of the Bedouins made of Wabir (camel or goat fur) or wool, not of hair (from other pelts). And it would have two or three posts." (An-Nihayah)

Seclusion in the Masjid for the sake of devotion to Allah.

Sunan an-Nasa'i Book 8, Hadith 22