أَوْحَى (inspired): This is a hidden inspiration, so Allah (swt) will inspire to the earth and this inspiration is not idiomatic, as some people think, rather it carries linguistic meaning as that mentioned in Surah An-Nahl:

  ٰ﴾وَأَوْحَىٰ رَبُّكَ إِلَى النَّحْلِ أَنِ اتَّخِذِي مِنَ الْجِبَالِ بُيُوتًا وَمِنَ الشَّجَرِ وَمِمَّا يَعْرِشُونَ﴿

(And your Lord inspired to the bee, “Take for yourself among the mountains, houses, and among the trees and [in] that which they construct.) (An-Nahl: 68)

And it is as the inspiration to the angels:

 ﴾ إِذْ يُوحِي رَبُّكَ إِلَى الْمَلَائِكَةِ أَنِّي مَعَكُمْ فَثَبِّتُوا الَّذِينَ آمَنُوا ۚ سَأُلْقِي فِي قُلُوبِ الَّذِينَ كَفَرُوا الرُّعْبَ فَاضْرِبُوا فَوْقَ الْأَعْنَاقِ وَاضْرِبُوا مِنْهُمْ كُلَّ بَنَانٍ ٰ﴿

([Remember] when your Lord inspired to the angels, “I am with you, so strengthen those who have believed. I will cast terror into the hearts of those who disbelieved, so strike [them] upon the necks and strike from them every fingertip.”) (Al-Anfal: 12)

And as the inspiration to Um-Musa, as well:

 ﴾وَأَوْحَيْنَا إِلَىٰ أُمِّ مُوسَىٰ أَنْ أَرْضِعِيهِ ۖ فَإِذَا خِفْتِ عَلَيْهِ فَأَلْقِيهِ فِي الْيَمِّ وَلَا تَخَافِي وَلَا تَحْزَنِي ۖ إِنَّا رَادُّوهُ إِلَيْكِ وَجَاعِلُوهُ مِنَ الْمُرْسَلِينَ ٰ﴿

(And We inspired to the mother of Moses, “Suckle him; but when you fear for him, cast him into the river and do not fear and do not grieve. Indeed, We will return him to you and will make him [one] of the messengers.”) (Al-Qasas: 7)

Also, as the inspiration to

 ﴾وَإِذْ أَوْحَيْتُ إِلَى الْحَوَارِيِّينَ أَنْ آمِنُوا بِي وَبِرَسُولِي قَالُوا آمَنَّا وَاشْهَدْ بِأَنَّنَا مُسْلِمُونَ ٰ﴿

 (And [remember] when I inspired to the disciples, “Believe in Me and in My messenger Jesus.” They said, “We have believed, so bear witness that indeed we are Muslims [in submission to Allah].”) (Al-Maaidah: 111)

So, the earth will understand what Allah (swt) wants, as Allah has prepared it, so it will shake.