The Midrash in Eichah distinguishes the context of Moshe’s use of the word “eichah” from the ways in which Yeshayahu and Yirmiyahu use the same word. Moshe was lamenting his obligation to deal personally with Klal Yisrael‘s petty complaints. On the other hand, Yeshayahu lamented Bnei Yisrael‘s unfaithfulness to Hashem. vbuzk v,hv vfht, “How had the faithful city become like a harlot,” he cried out. Yirmiyahu, who saw their humiliation and destruction cried out, vfht ssc vcah, “Alas, she (Klal Yisrael) sits in solitude.” The commentators differentiate among these three “eichahs” as referring to distinct stages of Klal Yisrael‘s iniquity.
Horav Ze’ev Weinberger, Shlita, adds an interesting thought. The three laments focus upon when the people realized that Klal Yisrael was in “trouble.” Yirmiyahu acknowledged it only when he saw actual churban. When he took note of their disgrace, the loss of their homeland and spiritual center, he grieved. Yeshayahu was able to recognize the dangerous route on which they were travelling much earlier. He noted when Bnei Yisrael acted like a harlot, when they tread upon “both thresholds,” when they sought the approval of the gentile nations who surrounded them. Indeed, when they wanted to be like the pagans, then Yeshayahu grieved. He saw where the gradual assimilation was heading. One cannot be a Jew and act and live like a gentile. One cannot have one foot in shul and the other in a pagan house of worship.
It was Moshe Rabbeinu, the father of all prophets, who predicted the downfall. As soon as the people clamored for intermediaries, officers for tens and officers for hundreds and thousands, he sensed a slow departure from tradition. He knew what had motivated their request. He saw the beginning of a digression which would lead to the churban Bais Ha’Mikdash.
It is important to note every change in our own behavior and attitude. The slightest deviation from the path of truth results in an insurmountable chasm that will ultimately devastate our spiritual well-being.