Surah Isra begins with:
سبحان الذي أسرى بعبده
Glory to (Allah) Who did take His servant for a Journey by night from the Sacred Mosque to the farthest Mosque...
And Surah Kahf begins with:
الحمد لله الذي أنزل على عبدهPraise be to Allah, Who has sent to His Servant the Book...
Notice the similarities and differences here? Both are glorifying and praising Allah, and both are discussing revelation.
In Surah Isra, the Prophet (sal-Allahu alayhi was-Sallam) is ascending up to receive the revelation, and in Surah Kahf the revelation is being sent down.
Both of them have the word ‘abdihi [His slave].