Lukas 9:58

9:58 Jesus said to him, “Foxes have dens and the birds in the sky ¹  have nests, but the Son of Man has no place to lay his head.” ² 

Lukas 17:24

17:24 For just like the lightning flashes ³  and lights up the sky from one side to the other, so will the Son of Man be in his day. ⁴ 

[9:58]  ¹ tn Grk “the birds of the sky” or “the birds of the heaven”; the Greek word οὐρανός (ouranos) may be translated either “sky” or “heaven,” depending on the context. The idiomatic expression “birds of the sky” refers to wild birds as opposed to domesticated fowl (cf. BDAG 809 s.v. πετεινόν).

[9:58]  ² sn Jesus’ reply is simply this: Does the man understand the rejection he will be facing? Jesus has no home in the world (the Son of Man has no place to lay his head).

[17:24]  ³ sn The Son of Man’s coming in power will be sudden and obvious like lightning. No one will need to point it out.

[17:24]  ⁴ tc Some very important mss (Ì⁷⁵ B D it sa) lack the words ἐν τῇ ἡμέρα αὐτοῦ (en th Jhmera autou, “in his day”), but the words are included in א A L W Θ Ψ Ë^1,13 Ï lat sy bo. On the one hand, the shorter reading is impressive because it has some of the best Alexandrian and Western witnesses in support; on the other hand, the expression ἐν τῇ ἡμέρα αὐτοῦ is unusual (found nowhere else in the NT), and may be considered the harder reading. A decision is difficult, but it is probably best to retain the words. NA²⁷ rightly has the words in brackets, expressing doubt as to their authenticity.