Isaiah 30:29

30:29 You will sing

as you do in the evening when you are celebrating a festival.

You will be happy like one who plays a flute

as he goes to the mountain of the Lord, the Rock who shelters Israel. ¹ 

[30:29]  ¹ tn Heb “[you will have] joy of heart, like the one going with a flute to enter the mountain of the Lord to the Rock of Israel.” The image here is not a foundational rock, but a rocky cliff where people could hide for protection (for example, the fortress of Masada).