أَلْقَتْ: Means that it throws out that within it from the dead, the treasures and the secrets.

تَخَلَّتْ  (relinquished): comes after the word (وَأَلْقَتْ)  (cast out) reflects a kind of cautiousness. In other words, the earth takes out everything inside it and does not keep anything, no matter how it is simple, rather it takes it out, utter it and empties it.