Do the mountains stop the earth from shaking?

Does Quran 21:31 mean the mountains prevent the earth from moving also same with Jami` at-Tirmidhi 3369 can someone explain it to me? Because the verse says that the mountains prevent the earth from moving and I am confused. Quran 21:31 > And We have placed firm mountains upon the earth so it does not shake with them, and made in it broad pathways so they may find their way > Jami` at-Tirmidhi 3369 >The Prophet said: “When Allah created the earth, it started shaking. So He created the mountains, and said to them: ‘Upon it’ so it began to settle.