Cited together with 19:17 because Jesus being called 'a spirit from Allah' was used to argue that Islamic texts already push Jesus beyond a merely ordinary human category.
Scripture spotlight
Quran 4:171
quran
171 People of the Book, go not beyond the bounds in your religion, and say not as to God but the truth. The Messiah, Jesus son of Mary, was only the Messenger of God, and His Word that He committed to Mary, and a Spirit from Him. So believe in God and His Messengers, and say not, 'Three.' Refrain; better is it for you. God is only One God. Glory be to Him -- That He should have a son! To Him belongs all that is in the heavens and in the earth; God suffices for a guardian.
Read in Arabic and English to argue that the Quran itself identifies Jesus as Allah’s word and a spirit from him, which the host used for a Christological argument against Islam.
The host cited this Quran verse to highlight that it calls Jesus 'the Word of Allah' and 'a Spirit from Him,' while also noting the anti-Trinitarian line 'do not say three' to argue that Muslims selectively use the verse.
Quoted to argue that the Qur'an explicitly rejects saying 'three' and therefore rejects the Trinity.
Cited to show that the Qur'an itself explicitly calls Jesus Allah's Word and a Spirit from Him, against claims that all prophets or all people are equally 'the word of Allah.'