Canto 3 -
Araṇya-kāṇḍa
Chapter 2: Rāma Encounters the Rākṣasa Virādha
Text 3.2.18

या न तुष्यति राज्येन पुत्रार्थे दीर्घदर्शिनी।
ययाहं सर्वभूतानां हितः प्रस्थापितो वनम्।
अद्येदानीं सकामा सा या माता मम मध्यमा॥

yā na tuṣyati rājyena putrārthe dīrgha-darśinī
yayāhaṁ sarva-bhūtānāṁ hitaḥ prasthāpito vanam
adyedānīṁ sakāmā sā yā mātā mama madhyamā

= she; na = and not; tuṣyati = satisfied; rājyena = with [merely procuring] the kingdom; putra-arthe = for her son; dīrgha-darśinī = was foresighted; yayā = because of her; aham = I; sarva-bhūtānām = to all creatures; hitaḥ = who do good; prasthāpitaḥ = have been sent; vanam = to the forest; adya = today; idānīm = right now; sakāmā = will attain her desires; = that lady; = who is; mātā = mother; mama = My; madhyamā = middle.

That lady who is My middle mother will attain her desires today, right now. She was foresighted and not satisfied with [merely procuring] the kingdom for her son. Because of her I, who do good to all creatures, have been sent to the forest.

Lord Rāma elaborates here on what Queen Kaikeyī wanted [to happen to Him] with penetrating insight.

If the foresighted Kaikeyī-devī hadn’t thought of a calamity for Rāma, Lakṣmaṇa and Sītā in the past, she would have only asked [her husband] for the boon of a kingdom for her son. She would not have asked for Rāma to be banished.

Because of her [request for a] boon that Rāma should be banished, it can be inferred that Kaikeyī must have certainly thought, “If He goes to the forest, Sītā will also go and she will be kidnapped by the rākṣasas and so on. Because of that, Rāma will experience a great calamity. And because of that, my son will have a kingdom devoid of any thorns.”1

Mātā mama madhyamā. Śrī Rāma has previously referred to Queen Kaikeyī as His youngest mother.2 This was in consideration of the three chief queens [of King Daśaratha]. In consideration of all of King Daśaratha’s wives, she was Lord Rāma’s middle mother. It has already been mentioned that Daśaratha had 350 wives.

GLOSS. Mātā mama madhyamā also indicates that Queen Kaikeyī was a madhyamā lady, that is, one who acts according to another’s instruction or instigation. By herself Kaikeyī was of good intelligence, but she acted on the instigation of Mantharā and therefore she is referred to as madhyamā.3

1 Kaikeyī thought, “When Rāma is greatly afflicted by the absence of Sītā, He would be incapable of taking over my son’s kingdom and so my son will be able to rule the kingdom without any interference from Rāma. 

2 Rāmāyaṇa 2.22.30.

3 Rāmāyaṇa-bhāva-dīpa: athavā madhyamā uktakāriṇī. svataḥ-sad-buddhitvān mantha-roktakāriṇīti proktakāriṇīty arthaḥ. “proktakārī tu madhyamaḥ” ity ukteḥ.