What is the difference between "ibtila’" (trial/test) and "bala’" (affliction/calamity), as in His, the Almighty’s, sayings: "And when He tried" and "We tried them"?

The meanings of "ibtalaa" (ابتلى) and "balaa" (بلى) are one, which is testing and trial. However, "ibtalaa" is more emphatic due to its increased structure. Al-Qurtubi interpreted both as meaning examination and testing, as in the Almighty's saying: ﴿And [mention, O Muhammad], when Abraham was tried by his Lord with commands and he fulfilled them.﴾ [Surat Al-Baqarah 2:124] and ﴿And We tried them with good [times] and bad [times] that perhaps they would return [to obedience].﴾ [Surat Al-A'raf 7:168].