Translation of Sarga 67 (vv. 1-12; Balakanda) from the Ramayana

जनकस्य वचः श्रुत्वा विश्वामित्रो महामुनिः |
धनुर् दर्शय रामाय इति ह उवाच पार्थिवम् ||1||

ततः स राजा जनकः सचिवान् व्यादिदेश ह |
धनुर् आनीयताम् दिव्यम् गन्ध माल्य अनुलेपितम् ||2||

जनकेन समादिष्ठाः सचिवाः प्राविशन् पुरम् |
तत् धनुः पुरतः कृत्वा निर्जग्मुः अमित औजसः ||3||

नृणाम् शतानि पंचाशत् व्यायतानाम् महात्मनाम् |
मंजूषाम् अष्ट चक्राम् ताम् समूहुः ते कथंचन ||4||

ताम् आदाय तु मंजूषाम् आयसीम् यत्र तत् धनुः |
सुरोपमम् ते जनकम् ऊचुः नृपति मन्त्रिणः ||5||

इदम् धनुर् वरम् राजन् पूजितम् सर्व राजभिः |
मिथिला अधिप राज इन्द्र दर्शनीयम् यत् इच्छसि ||6||

Having heard the words of Janaka, the great sage Viśvāmitra said to the king, “Show the bow to Rāma.” ||1|| Thus, King Janaka instructed his vassals, “Let the divine bow, adorned with fragrant garlands, be brought forth.” ||2|| The vassals commanded by Janaka entered the citadel. Having placed the bow in front, they exited according to [or “in accordance with”] the king’s command. ||3|| The 5,000 great-souled, strong men somehow pulled the eight-wheeled chest. ||4|| Having placed [down] the iron casket in which the bow lies, the vassals said to the God-like King: ||5|| “That precious bow here, O Sovereign King of Mithilā, which you desire to be seen, is revered by all kings.” ||6||

तेषाम् नृपो वचः श्रुत्वा कृत अंजलिः अभाषत |
विश्वामित्रम् महात्मानम् तौ उभौ राम लक्ष्मणौ ||7||

इदम् धनुर् वरम् ब्रह्मन् जनकैः अभिपूजितम् |
राजभिः च महा वीर्यैः अशक्तैः पूरितम् तदा ||8||

न एतत् सुर गणाः सर्वे स असुरा न च राक्षसाः |
गंधर्व यक्ष प्रवराः स किन्नर महोरगाः ||9||

क्व गतिः मानुषाणाम् च धनुषो अस्य प्रपूरणे |
आरोपणे समायोगे वेपने तोलने अपि वा ||10||

तत् एतत् धनुषाम् श्रेष्ठम् आनीतम् मुनिपुंगव |
दर्शय एतत् महाभाग अनयोः राज पुत्रयोः ||11||

विश्वामित्रः स रामः तु श्रुत्वा जनक भाषितम् |
वत्स राम धनुः पश्य इति राघवम् अब्रवीत् ||12||

Having heard those words, the king did the añjali and said to the great-souled Viśvāmitra and both Rāma & Laksmana: ||7|| “This bow, O Brahmin, was honored by ancestors and by the most virile kings, all unable to draw it. ||8|| Nor the Suraganas, Asuras, or Raksasas, headed by the Gandharvas & and Yaksas, along with the Kinnaras & Mahoragas. ||9|| What is the path of humans in drawing the bow, in stringing, in fitting the arrow, in brandishing it, and even in raising it? ||10|| Viśvāmitra, chief among sages, let that most excellent bow be shown to the two princes, O Undivided One.” ||11| Having heard that which was spoken by Janaka, the great-souled Viśvāmitra said to the descendent of Raghu, “O young Rāma, see the bow.” ||12|| 

Marking 'lineage' via the inst. pl.?

I’m going to collect some thoughts here on my class translations of sargas from the Valmiki Rāmāyana. I’m having some trouble with the following सर्ग, no. 67, in the बालकाण्ड:

इदं धनुर्वरमं ब्रह्मञ्जनकैरभिपूजितं ॥

राजभिश्च महावीर्यैरशक्तैः पूरितुं पुरा ॥8॥

At this point, Śiva’s bow has been presented to Janaka by his vassals, and he says the above to विश्वामित्रं महात्मानं तौ चोभौ रामलक्श्मणौ (“..the great-souled Viśvamitra and both Rāma and Lakśmana”) after performing the añjali. I think the above verse just functions as Janaka‘s explanation, mostly to Rāma, of the history of the bow.

So what’s up with all of the instrumental plurals? Janakaih., Rājabhih., etc.? The first instance is followed by abhi-pūjitam. My first thought was that it could –– somehow –– be thought of as, “That divine bow, deeply venerated by Janakas,” weirdly pluralized… So I wonder whether there exists an idiomatic use of the instrumental plural as denoting ancestry or lineage? This would make it, “That divine bow, deeply venerated by the lineage of Janaka.” (Though it’s a bit odd that his own lineage would be referred to in the 3rd person.) I’ve seen similar translations online, but can’t find any sources explaining this idiomatic use –– assuming I’m interpreting it right…