When you see
You should know
That he is near,
At the very gates.”
οὕτως καὶ ὑμεῖς, ὅταν ἴδητε ταῦτα γινόμενα, γινώσκετε ὅτι ἐγγύς ἐστιν ἐπὶ θύραις.
This is almost word for word in Matthew, chapter 24:33, and in Luke, chapter 21:31, except that Luke mentioned the Kingdom of God was near, not he or it was near. Mark said that Jesus explained that when they saw these things like the budding trees, they should know that he, the Son of Man, was near. The end times were coming. When they saw all these things happening (οὕτως καὶ ὑμεῖς ὅταν ἴδητε ταῦτα γινόμενα), they should know that the end or he was near, at the gates to their city or the doors to their houses (γινώσκετε ὅτι ἐγγύς ἐστιν ἐπὶ θύραις). There would be these prior signs indicating what was to come.