Verse 47

अशनिस्वनघोषेण नगस्फोटरवेण च ।ऐरावणनिनादेन सम्यग्ध्यानी न कम्पते

In plain words

By the roar of the thunderbolt's report, by the crashing burst of a mountain, and by the roar of Airāvaṇa, one of true meditation does not tremble.